Keep the resource WMS url params when creating the map with MapStore

[afabiani]

When creating a map, the client looks for the links > WMS > url parameters in order to build the base WMS GetMap URL.

There are cases where the resource WMS url contains some custom parameters, e.g.:

"links": [
      {
        "extension": "html",
        "link_type": "OGC:WMS",
        "name": "OGC WMS: httpwww502regionetoscanaitows_ofccomrtwmsrtmapwmsmapowsofcmap_resolution91 Service",
        "mime": "text/html",
        "url": "http://www502.regione.toscana.it/ows_ofc/com.rt.wms.RTmap/wms?map=owsofc&map_resolution=91"
      }
    ]

The client should keep those parameters and inject them into the WMS GetMap url